'Amerindianist' originates from the English combining form 'Amerindian' plus the agentive suffix '-ist' (from Late Latin/Greek via French), where 'Amerindian' itself is a blend of 'American' and 'Indian' referring to the indigenous peoples of the Americas.

'Amerindianist' was formed relatively recently in English by adding the suffix '-ist' to 'Amerindian'. 'Amerindian' emerged in the early 20th century as a blend of 'American' (from 'America', named after Amerigo Vespucci) and 'Indian' (from the historical term for peoples of the Indies), and the modern English coinage 'Amerindianist' developed to denote a specialist in that field.

Initially, 'Amerindian' meant 'relating to the indigenous peoples of the Americas'; over time 'Amerindianist' came to mean specifically 'a person who studies or advocates for those peoples', i.e., a specialist or scholar in Amerindian studies.